Prior to sale, a photovoltaic module must pass a series of electrical and mechanical tests to assess safety and reliability of the device. In particular, photovoltaic modules must pass a wet high-potential test. The test is useful to identify insulation flaws that may result in safety hazards during use and to identify moisture leaks that may result in reduced performance. In addition, the test is useful to evaluate a device's susceptibility to electrochemical corrosion when placed in a wet environment. During the test procedure, a photovoltaic module is submersed in a surfactant solution, and a high voltage (e.g. 500 V) is applied to a current-carrying conductor within the device. Leakage current is measured between the current-carrying conductor and an electrical ground within the test apparatus. The amount of leakage current provides an indication of the device's insulation quality. However, test data is highly dependant on test factors including surfactant temperature and surfactant conductivity. As a result, repeatability is lacking when the test parameters are permitted to fluctuate.